Lamp socket



Oct. 26, 1965 L, o os 3,214,724

LAMP SOCKET Filed Aug. 28, 1963 2 Sheets-Sheet 1 INVENTOR.

J Awe 6 m/ave? #mur A Home y Oct. 26, 1965 G. MCINTOSH LAMP SOCKET 2Sheets-Sheet 2 Filed Aug. 28, 1963 Attorney United States Patent Q3,214,724 LAMP SOCKET Lawrie G. McIntosh, Etobicoke, Ontario, Canada,assignor to Carillon Lighting Limited, Toronto, Ontario, Canada FiledAug. 28, 1963, Ser. No. 395,036 15 Claims. (Cl. 339-99) This inventionrelates to a lamp socket of a unique construction, to a new and usefuldevice for holding the parts of the housing of a lamp socket together,and to a new and useful electrical contact arrangement for a lampsocket.

Prior art types of lamp sockets generally are provided with a housingwhich is formed in two parts, with the parts .of the housing being heldtogether by screws, rivets or the like. It is a disadvantage in themanufacture of such sockets that to screw together the parts of thehousing of a lamp socket is a time consuming procedure, and a machine isrequired to perform the riveting operation, which also is a timeconsuming procedure.

With other types of lamp sockets a headed metal strip may be passedthrough the parts of the housing, the metal strip being bent over orotherwise deformed against one part of the housing to retain the partsof the housing together between the head and the deformed part. Such amode of fastening requires the provision of a bending machine or thelike, which, because it performs a separate operation, increases thetime consumed in and adds to the cost of assembling the parts of thehousing together. Furthermore, the deformed part is visible and detractsfrom the appearance of the socket.

Accordingly, one object of one aspect of this invention is to providepre-formed holding means which only need to be inserted into the partsof the housing of a lamp socket to maintain these parts together.

A further object of a preferred embodiment of this aspect of theinvention is to provide holding means for holding together the parts ofthe housing of a lamp socket, the holding means being formed integralwith a spring clip which is employed to fasten the lamp socket to a treebranch or the like, and preferably not being visible from the side ofthe socket opposite to the holding means.

In the past many different types of electrical contact arrangements havebeen proposed for use wit-h lamp sockets. Generally speaking, the twoelectrical contacts of a lamp socket are completely dissimilar in shapeand appearance. These electrical contacts are made separately byseparate operations and then are inserted into the lamp socket andsubsequently connected to electrical conductors, or are first connectedto the electrical conductors and then placed in the lamp socket. I

It is an object of another aspect of this invention to provide a set ofelectrical cont-acts which can be made in simple steps from a singlestrip of material.

A further object of this aspect of the invention is to provide a set ofcontacts which are assembled on electrical conductors from the same sidethereof, so that when the electrical contacts are positioned in thehousing of a socket, the contacts are oriented in one part of thehousing of the socket, enabling a recess to be provided in the otherpart of the housing of the socket to accommodate a tree branch or thelike, thus permitting the socket to be positioned more closely towardsthe centre of the tree branch.

An additional object of still a further aspect of this invention is toprovide a housing for a lamp socket, the housing being constructed intwo parts with one part carrying die members which serve, when the partsof the housing are closed upon each other, to orient the contactsproperly in the housing.

The various aspects of this invention and its advantages will becomemore apparent from the following detailed description taken inconjunction with the drawings? in which:

FIGURE 1 is a perspective view of a lamp socket embodying thisinvention;

FIGURE 2 is a section taken along line 2-2 in FIG- URE 1;

FIGURE 3 shows in section a modified form of part of a lamp socketembodying this invention;

FIGURE 4 is a view showing the manner of assembling electrical contactsembodying this invention;

FIGURES 5 and 6 are perspective views showing the interiors of the twoparts of the housing of a lamp socket embodying this invention; and

FIGURE 7 is a View similar to FIGURE 5 but showing the electricalcontacts and conductors in position, the part of the housing of the lampsocket shown in FIG- URE 6 being illustrated in ghost outline.

Referring to FIGURES 1-3 and 5-7, a lamp socket 1t) embodying thisinvention comprises a housing molded in two parts .11 and 12 of anysuitable electrical insulating material. Positioned in the lamp socketare electrical contacts 13 and 14 made of copper or any other suitableelectrically conductive material. Electrical contacts 13 and 14 will bediscussed in greater detail hereinafter, but, for present purposes, itis sufiicient to note that contacts 13 and 14 are electrically connectedto wires in insulated conductors 15 and 16 respectively by means ofinsulation piercing pins 17 and 18 which penetrate the insulation ofelectrically insulated conductors 15 and 16 and electrically contact theelectrically conductive wires within the insulation.

Part 11 of the housing has an opening 19 extending therethrough, whilepart 12 of the housing has an opening 20 therein which does not extendcompletely through part 12 but terminates short of the outer surface ofpart 12 in a wall 20a, as best shown in FIGURE .2. Both openings .19 and20 are of square cross-section.

In accordance with one aspect of this invention, a new and usefulholding device 21 which is best shown in FIG- URE 2, and which is alsoshown in part in FIGURE 1 is provided. Holding device 21 comprises astrip 22 of spring metal which carries a spring finger 23 at one endthereof, spring finger 23 being generally hook-shaped and projectingsideways from strip 22. Strip 22 preferably is formed integral with aspring finger 24 by cutting strip 22 from spring finger 24, bend-ingstrip 22 downwardly at.

approximately right angles to spring finger 24, thereby leaving anopening 25 in spring finger 24, and bending spring finger 23 to thehook-shaped configuration shown in FIGURE 2. Spring finger 24 serves asthe head of holding device 21 and has a circular opening 26 therein.

In order to retain parts 11 and 12 of the housing together, strip 22carrying spring finger 23 is inserted into openings 1-9 and 20 to theposition shown in FIGURE 2. Opening 26 in spring finger 24 co-operateswith a pin 27 provided in a recess 28 in part 11 of the housing in sucha manner that pin 27 restrains spring finger 24 from lateral movementwith respect to part 11, while any tendency for spring finger 24 topivot about pin 27 is prevented by the abutment of those outside edgesof spring finger 24 which are adjacent opening 26 with the side wallsdefining recess 28. Spring finger 23 is so dimensioned that uponinsertion of strip 22 into openings 19 and 20, spring finger 23 isflexed and, therefore, in the position shown in FIG- URE 2, is biasedagainst one side wall 29 of opening 20.

From the foregoing it will be seen that parts 11 and 12 of the housingmay be held together by the very simple operation of pressing holdingdevice 21 into place, and that separation of parts 11 and 12 is stronglyresisted by holding device 21, since any attempt to remove holdingdevice 21 from the position of FIGURE 2 immediately results in springfinger 23 digging into side wall 29.

Should it ever be necessary to remove holding device 21, wall a can bepenetrated and a thin strip of metal slid along wall'29, thus enablingholding device 21 to be removed, but once holding device 21 has beenlocated, it should not be necessary to remove it.

While the holding device which is shown in FIGURES 1 and 2 is apreferred embodiment of this aspect of the invention, since the holdingdevice can be formed integral with a spring finger 24 used for securingthe lamp socket to a tree branch or the like, spring finger 24 actuallyforming the head of the holding device, it will be appreciated that inless preferred embodiments of this aspect of the invention the head ofstrip 22 may take a different form. For example, in FIGURE 3 there is nospring finger 24 associated with holding device 21, spring finger 24being replaced by a more conventional head 311 in the form of part of asphere, head bearing against part 11 of the housing adjacent opening 19.Apart from this change, however, holding device 21 of FIGURE 3 is thesame as holding device 21 shown in FIGURE 2.

Another aspect of this invention is illustrated in detail in FIGURE 4.Turning to this figure, there are shown electrical contacts 13 and 14.Each of these contacts comprises a strip 13a and 140 respectively ofelectrically conductive material each bent upon themselves at one end toformgenerally hook-shaped ends 13b and 14b respectively. Each ofhook-shaped ends 1311 and 14b carry an electrically conductiveinsulation-piercing pin 17 and 18 respectively, these pins being formedintegral with strips 13a and 14a and being bent at approximately rightangles to the planes of strips 13a and 14a. Pin 18 is positioned closerto its hook-shaped end 14b than is pin 17 positioned relative to itshook-shaped end 1317, so that when contacts 13 and 14 are positionedside-by-side in gripping engagement with insulated electrical conductors15 and 16, as best shown at the bottom of FIGURE 4, pins 17 and 18 areoifset with respect to each other, and each pierces a different one ofinsulated conductors l5 and 16. However, it will be noted that both ofcontacts 13 and 14 grip conductors 15 and 16 and hold them in place.

'One end 140 of contact 14 is bent in the same plane as and overhook-shaped end 14b. Both contacts 13 and 14 have fingers 31 and 32respectively projecting therefrom intermediate the ends thereof. Fingers31 and 32 point towards each other when electrical contacts 13 and 14are mounted on insulated electrical conductors 15 and 16, as best shownin the lower part of FIGURE 4.

As most readily seen in FIGURES 4 and 7, insulated electrical conductors15 and 16 are mounted one on top of the other in hook-shaped ends 1311and 14b, with both conductors being gripped and held in position by bothhook-shaped ends. However, pin 17 electrically contacts the wire ininsulated conductor 15, while pin 18 electrically contacts the wire ininsulated conductor 16.

It is important to note that both electrical contacts 13 and 14 aremounted on insulated conductors 15 and 16 from the same side thereof.This is of considerable importance in facilitating the assembly of theelectrical contacts on the insulated conductors.

Because of the nature of electrical contacts 13 and 14, they can readilybe made from a single strip of conductive material which is shown inFIGURE 4 at 33. This strip of material has spaced-apart openings 34therein. In the manufacture of contacts 13 and 14, strip 33 is severedalong line 35 so that the cut-off part 36 is of generallyH-configuration. In a subsequent operation pins 17 and 18 and part 140are bent downwardly, and at the same time, fingers 31 and 32 are severedalong a line therebetween to form the separate electrical contacts 13and 14. These contacts then may be mounted on insulated conductors 15and 16 by bending ends 13b and 14b over the conductors, which causespins 17 and 18 to pierce the insulation of insulated conductors 15 and16 and causes both contacts to grip both insulated conductors 15 and 16.

Because of the particular configuration of electrical contacts 13 and14, they can both be made from a single strip of material by simplebending and cutting operations, and they can readily be assembled oninsulated conductors 15 and 16, because of the fact that they aremounted on one side rather than on both sides of insulated conductors 15and 16. It will be seen that the nature of electrical contacts 13 and 14permits ready assembly of sets of these contacts in spaced-apartrelationship upon insulated conductors 15 and 16, as is required in theprovision of a Christmas tree lighting set, for example. All that isnecessary is that conductors 15 and 16 be advanced to a work stationwhere the electrical contacts are mounted on the conductors, and theconductors then be further advanced so as to bring other portionsthereof to the work station for repeating of the previous operation.

A third aspect of this invention is best illustrated in FIGURES 2, 5, 6and 7. Referring to these figures, it will be seen that parts 11 and 12of the housing have a threaded opening 37 formed therein which isadapted to receive the base of a light bulb 38 (shown in ghost outlinesin FIGURE 1). It will be seen that one half of opening 37 is formed ineach of parts 11 and 12.

Part 11 of the housing of lamp socket 10 has two die members 39 and 40molded therein and positioned below the part of opening 37 provided inhousing part 11. Die member 40 is positioned beneath die member 39. Diemember 39 has sides 41 and 42 which are inclined with respect to eachother at approximately right angles, these sides 41 and 42 beingseparated by a flat surface 43 through which opening 19 extends and aprojecting lip 44 having a flat upper surface 45 and an inclined sidesurface 46. The top surface 47 of die member 39 is fiat and forms thebase of opening 37.

Die member 40 is set in a channel 48 which extends part way through part11 of the housing. Die member 40 has sides 49 which are inclined withrespect to each other at an angle slightly less than 90 and whichterminate in an upwardly projecting lip 50. Recesses 51 are provided inthe side walls of part 11.

Part 12 of the housing is provided with longitudinally extending keys 52which engage in recesses 51 when parts 11 and 12 are placed together, soas to prevent relative sliding movement between parts 11 and 12. Part 12has a cavity 53 which is adapted to receive die members 39 and 40.Connecting with cavity 53 is a channel 54 which coacts with channel 48to provide an opening through which conductors 15 and 16 may enter thehousing of the lamp socket, this opening being designated 55 in FIGURES1 and 2. Also, as best shown in FIGURE 6, a channel 56 is provided inpart 12 in the threaded part of Opening 37.

As best seen in FIGURES 1 and 2, a recess 57 is provided in part 11 withspring finger 24 extending over recess 57.

In order to assemble a lamp socket embodying this invention, theelectrical contact assembly shown in the bottom part of FIGURE 4 is laidin part 11 of the hous ing with the parts of insulated conductors'lS and16 between contacts 13 and 14 lying across lip 50 of die member 40, andwith fingers 31 and 32 lying on flat surface 45. Part 12 then ispositioned over part 11 in the manner shown in FIGURE 7 and is pressedtowards part 11. This action causes insulated conductors 15 and 16 to bebent over die member 40, as best shown in FIG- URE 7. This actionadditionally causes electrical contacts 13 and 14 to spread apart, bothcontacts eachbeing moved through an angle of about so that bent part 14cturns across surface 47 and extends to the centre thereof, while thecorresponding end of contact 13 positlons itself in channel 56 andextends into opening 37. This is the position of contacts 13 and 14shown in FIG- URE 7, where it also will be noted that fingers 31 and 32lie against surfaces 42 and 41 respectively, as do strips 13a and 14a.Edges 39a of die member 39 serve as stops for electrical contacts 13 and14.

A lamp socket made from parts 11 and 12 of the housing shown in FIGURES5 and 6 is intended as a series socket, in view of the fact that opening55 does not extend completely through the socket. In such a seriessocket conductors and 16 are out within the socket, as shown in solidoutlines in FIGURE 7. If it is intended, however, that lamp sockets beconnected in parallel, the socket illustrated is merely modified bycontinuing channels 54 and 48 completely through both parts 11 and 12 ofthe housing, so that conductors 15 and 16 may pass completely throughthe housing, as shown in dotted lines in FIGURE 7.

After the parts of the housing have been assembled in the aforementionedmanner, holding device 21 is placed in the position shown in FIGURE 2,whereupon a com plete lamp socket is formed.

An important feature of the construction of a lamp socket embodying thisinvention is that it can be readily assembled without the necessity ofseparately inserting contacts in recesses provided in the housing partof the socket, and the sockets lend themselves to ready assembly onconductors bearing a plurality of spaced apart sets of electricalcontacts 13 and 14, as is the case with Christmas tree light sets, forexample. A further important feature is the fact that all but part 140of the electrical contacts are carried in part 12 of the housing of lampsocket 10, thus permitting the provision of recess 57 to accommodate atree branch or the like, so as to enable the socket to be more closelycentred on the tree branch without having to extend the length of thesocket. Another important feature of such a socket is that it can beused for series or parallel wiring without modification of the contactarrangement and without modification of housing parts 11 and 12, except,of course, that a socket for parallel wiring requires an opening 55extending completely therethrough, whereas a socket for series wiringdoes not necessarily.

While there has been disclosed herein preferred ernbodiments of thisinvention, those skilled in the art will appreciate that changes andmodifications may be made therein without departing from the spirit andscope of this invention as defined in the appended claims.

What I claim as my invention is:

1. A lamp socket comprising a housing formed in at least two parts,electrical contacts, said electrical contacts being positioned in saidhousing, a first spring finger mounted on said housing, a member formedintegral with Said first spring finger, partially cut-away therefrom andbent away from said first spring finger, said member carrying agenerally hook-shaped second spring finger remote from said first springfinger, a first One of said parts of said housing having a first openingextending therethrough, a second one of said parts of said housinghaving a second opening extending only part way therethrough and definedby side walls, said member extending through said first opening, saidsecond spring finger being inserted in said second opening and being ina flexed position in said second opening, a part of said second springfinger bearing against one of said side walls of said second openg,whereby withdrawal of said member from said housing is resisted, saidfirst spring finger bearing against said first part of said housing,said member in conjunction with said first spring finger holding saidparts of said housing together.

2. A lamp socket according to claim 1 wherein there is a recess formedin said first part of said housing, said first spring finger extendingover said recess and cooperating therewith to provide means for mountingsaid socket on a branch or the like.

3. Means for conducting electrical energy to a lamp socket comprising aplurality of insulated electrical conductors and a set of electricalcontacts, each contact of said set of contacts comprising a strip ofelectrically conductive material bent upon itself at one end to form agenerally hook-shaped end, said hook-shaped end carrying an electricallyconductive insulation-piercing pin, one of said pins being positionedcloser to its hook-shaped end than the other of said pins, whereby whensaid contacts are positioned side-by-side in gripping engagement withsaid insulated electrical conductors said pins are offset with respectto each other, the end of one of said contacts remote from saidhook-shaped end thereof being bent in the same plane as and over saidhook-shaped end thereof, said insulated electrical conductors beingmounted one on top of the other in said hook-shaped ends and all beinggripped and held in position by said hook-shaped ends, said electricalcontacts both being mounted on said insulated electrical conductors fromthe same side thereof, said pins piercing the insulation of differentones of said insulated electrical conductors and electrically contactingdifferent ones of said conductors.

4. The invention according to claim 3 wherein each of said strips ofmaterial has a finger projecting therefrom intermediate the ends of saidstrip of material, said fingers pointing towards each other when saidelectrical contacts are mounted on said insulated electrical conductors.

'5. The invention according to claim 3 wherein said insulated electricalconductors are bent between said electrical contacts.

6. A lamp socket comprising a housing formed in two parts, a pluralityof electrical contacts, said electrical contacts being positioned insaid housing, and means for holding said parts of said housing together,said socket having an opening therein adapted to receive the base of alight bulb, a part of said opening being formed in both of said parts ofsaid housing, one of said parts of said housing having first and seconddie members positioned below the part of said opening formed in said onepart of said housing with said second die member beneath said first diemember, said first die member having sides angularly inclined towardseach other, said die members projecting into a cavity in said other partof said housing beneath said part of said opening formed in said otherpart of said housing, and electrical conductors passing into saidhousing, said electrical contacts electrically contacting diiferent onesof said electrical conductors and being in spaced-apart relationshipwith respect to each other, the portion of said electrical conductorsbetween said electrical contacts being bent over said second die member,one of said electrical contacts resting against one of said angularlyinclined sides of said first die member, the other of said electricalcontacts resting against the other of said angularly inclined sides ofsaid first die member.

7. A lamp socket according to claim 6 wherein said sides of said firstdie member are at an angle of about to each other.

8. A lamp socket according to claim 6 including a recess formed in saidone part of said housing and adapted to accommodate the branch of a treeor the like.

9. A lamp socket according to claim 6 wherein said first die member hasan upper surface, said upper surface forming the bottom of said opening,one of said electrical contacts having a bent-over portion lying acrosssaid upper surface, said other part of said housing having an openchannel therein extending along the side wall defining said part of saidopening in said other part of said housing, a part of the other of saidelectrical contacts lying in said channel.

-10. A lamp socket according to claim 6 wherein said one part of saidhousing has a first opening extending therethrough, said other part ofsaid housing has a second opening therein defined by second side walls,said holding means comprising a member having a head and carrying aspring finger projecting sideways from said member and positioned remotefrom said head, said member extending through said first opening, saidspring finger being inserted in said second opening and being in aflexed position in said second opening, a part of said spring fingerbearing against one of said second side walls of said second opening,whereby withdrawal of said holding means from said housing is resisted,said spring finger in conjunction with said member holding said parts ofsaid housing together.

11. A lamp socket according to claim 10 wherein said head comprises aspring finger.

12. A lamp socket according to claim 11 wherein there is a recess formedin said one part of said housing, said last-mentioned spring fingerextending over said recess and co-operating therewith to provide meansfor mounting said socket on a branch or the like, said last-mentionedspring finger being formed integral with said member.

13. A l-amp socket according to claim 6 wherein said electricalconductors are insulated, each of said contacts comprising a strip ofelectrically conductive material bent upon itself at one end to form agenerally hook-shaped end, said hook-shaped end carrying an electricallyconductive insulation-piercing pin, one of said pins being positionedcloser to its hooked-shaped end than the other of said pins, wherebywhen said contacts are positioned side-by-side in gripping engagementwith said insulated electrical conductors said pins are ofiset withrespect to each other, the end of one of said contacts remote from saidhook-shaped end thereof being bent in the same plane 'as and over saidhook-shaped end thereof, said insulated electrical conductors beingmounted one on top of the other in said hook-shaped ends and all beinggripped and held in position by said hook-shaped ends, said electricalcontacts both being mounted on said insulated electrical conductors fromthe same side thereof, said pins piercing the insulation of differentones of said insulated electrical conductors and electrically contactingditferent ones of said conductors.

14. A lamp socket according to claim 13 wherein each of said strips ofmaterial has a finger projecting therefrom intermediate the ends of saidstrip of material, said fingers each resting against a different one ofsaid inclined sides of said first die member.

15. A lamp socket according to claim 13 wherein said one part of saidhousing has a first opening extending therethrough, said other part ofsaid housing has a second opening therein defined by second side walls,said holding means comprising a member having a head and carrying aspring finger projecting sideways from said member and positioned remotefrom said head, said member extending through said first opening, saidspring finger being inserted in said second opening and being in aflexed position in said second opening, a part of said spring fingerbearing against one of said second side walls of said second opening,whereby withdrawal of said holding means from said housing is resisted,said spring finger in conjunction with said member holding said parts ofsaid housing together.

References Cited by the Examiner UNITED STATES PATENTS 1,818,884 8/31Eckstein 339-99 2,704,832 3/55 Greenbaum 339l 57 X 3,127,229 3/64 Beck33999 3,151,926 10/64 Schick et al. 339-99 JOSEPH D. SEERS, PrimaryExaminer.

W. DONALD MILLER, Examiner.

1. A LAMP SOCKET COMPRISING A HOUSING FORMED IN AT LEAST TWO PARTS,ELECTRICAL CONTACTS, SAID ELECTRICAL CONTACTS BEING POSITIONED IN SAIDHOUSING, A FIRST SPRING FINGER MOUNTED ON SAID HOUSING, A MEMBER FORMEDINTEGRAL WITH SAID FIRST SPRING FINGER, PARTIALLY CUT-AWAY THEREFROM ANDBENT AWAY FROM SAID FIRST SPRING FINGER, SAID MEMBER CARRYING AGENERALLY HOOK-SHAPED SECOND SPRING FINGER REMOTE FROM SAID FIRST SPRINGFINGER, A FIRST ONE OF SAID PARTS OF SAID HOUSING HAVING A FIRST OPENINGEXTENDING THERETHROUGH, A SECOND ONE OF SAID PARTS OF SAIDHOUSING HAVINGA SECOND OPENING EXTENDING ONLY PART WAY THERETHROUGH AND DEFINED BYSIDE WALLS, SAID MEMBER EXTENDING THROUGH SAID FIRST OPENING, SAIDSECOND SPRING FINGER BEING INSERTED IN SAID SECOND OPENING AND BEING INA FLEXED POSITION IN SAID SECOND OPENING, A PART OF SAID SECOND SPRINGFINGER BEARING AGAINST ONE OF SAID SIDE WALLS OF SAID SECOND OPENING,WHEREBY WITHDRAWAL OF SAID MEMBER FROM SAID HOUSING IS RESISTED, SAIDFIRST SPRING FINGER BEARING AGAINST SAID FIRST PART OF SAID HOUSING,SAID MEMBER IN CONJUNCTION WITH SAID FIRST SPRING FINGER HOLDING SAIDPARTS OF SAID HOUSING TOGETHER.